1. Field of the Invention
The present invention relates to a sanitary napkin with a projection disposed on a body surface of a napkin body and more particularly to a sanitary napkin whose projection can easily conform to the contours of the woman's body so as to be effective in preventing leakage of menstrual blood.
2. Description of the Related Art
There have been known sanitary napkins with a napkin body containing a liquid-absorbent layer and a projection projecting from a body surface of the napkin body.
Japanese Unexamined Patent Application Publication No. H11-513921 discloses a sanitary napkin in which a primary absorbent component having a generally triangular cross section is disposed on a body surface of a secondary absorbent component. The primary absorbent component is constructed by wrapping a hydrophilic foam structure in an outer cover. The cross-sectional shape of the primary absorbent component does not change over the length of the sanitary napkin.
Japanese Unexamined Patent Application Publication No. H09-313529 discloses a sanitary napkin whose upper surface layer is centrally folded to form a jetty. This jetty has longitudinally-extending elastic members in its right and left side portions and is raised from the body surface of the napkin body under elastic tension exerted by the elastic members. The jetty extends longitudinally of the sanitary napkin with a uniform width.
Japanese Unexamined Patent Application Publication No. 2002-320638 discloses a sanitary napkin in which a T-section three-dimensional wall formed of a liquid-permeable sheet is disposed on the body surface of the napkin body. This three-dimensional wall has elastic members for exerting a longitudinal contractive force and is raised from the body surface of the napkin body when the napkin body is curved with front and rear edges of the napkin body being drawn closer to each other by the elastic members. The width of the three-dimensional wall does not change over the length of the napkin body.
Japanese Unexamined Patent Application Publication No. 2001-504727 discloses a sanitary napkin which has a liquid-absorbent layer and a topsheet disposed on a body surface of the liquid-absorbent layer with an absorbent body and a stiffening element interposed between the liquid-absorbent layer and the topsheet. The topsheet, the absorbent body, and the stiffening element form a hump having a generally triangular cross section. In the hump, both the width and height gradually increases from the front end to the center and gradually decreases from the center to the rear end.
In all these conventional sanitary napkins, a projection designed to fit against the wearer's body is disposed on the body surface of the napkin body so as to prevent leakage of liquid such as menstrual blood.
In the woman's crotch, however, the cleft varies in shape anteroposteriorly to have different opening widths and depths for different regions. Around the vaginal opening and the labia majora, the cleft has a relatively large opening width. Near and behind the anus, the cleft lies between the buttocks. The cleft between the buttocks (or the intergluteal cleft) becomes the deepest behind the anus and then shallower toward the coccyx.
Moreover, in order that the liquid absorbent layer of the sanitary napkin can effectively absorb liquid such as menstrual blood discharged from the vaginal opening, the sanitary napkin should reliably fit on the vaginal opening and its vicinity.
In the sanitary napkins disclosed in the Patent Publication Nos. H11-513921, H09-313529, and 2002-320638, however, the projection is uniform in width and does not change much in height over the length of the projection. Therefore, the projection, which is not in conformity with the contours of the woman's crotch, may cause a problem of failing to snugly fit on the vaginal opening or to reliably find its way into the intergluteal cleft.
In the sanitary napkin disclosed in the Patent Publication No. 2001-504727, on the other hand, both the width and the height become the largest centrally of the projection. When the center of the projection is applied to the vaginal opening and its vicinity, the projection tends to make a wearer feel uncomfortable because it is too high. When the center of the projection is applied to the intergluteal cleft, the projection cannot easily find its way into the intergluteal cleft because it is too wide. When the center of the projection is applied to the coccyx and its vicinity, the projection tends to create a gap between the napkin body and the buttocks because it is too high.